Armed with a 4x5 large-format camera and audio equipment, New York City-based photographer Chris Callaway has documented in intimate portraits and audio interviews the stories of these protesters. The images and audio capture the movement that has drawn people from around the world to help protect the lands that the Sioux Nation holds so dear.

“My objective is to personalize the protest by bringing the spirit, voice, and people of the camp to you,” Callaway told The Huffington Post in an email.

“As a photographer, I think it’s important to use my craft to help those whose voices can’t be heard.”